“Maintain eye contact, have pleasant facial expressions, an open posture, and relatively close proximity.”
Great advice, eh? Sure. Itʻll make the regularly-sighted peeps around you happy.
But Iʻm angry about every step of that advice. Itʻs from Interpersonal Communicationby Joseph A. DeVito, by Pearson. More about my rant on why here. Short version? I canʻt see your “plesant facial expressions” or your “open posture”. I can hear your “relatively close proximity”, and if you are talking to the direction of my voice or are actively listening or are all lost in your own world. Thatʻs enough.